Hemoglobin A1c-specific aptamer, hemoglobin-specific aptamer, and applications thereof

Abstract

The present invention provides a Hemoglobin A1c-specific aptamer and a Hemoglobin-specific aptamer. The aptamers were selected in vitro using SELEX and a microfluidic chip system. The aptamers established low free energy, thus were more stable than conventional antibodies. The high specificity of the aptamers to Hemoglobin A1c or Hemoglobin allows them to be effectively used in diagnosis of diabetes and/or anemia.

What is claimed is: 
     
       1. An aptamer that specifically binds to hemoglobin A1c, wherein the aptamer is a nucleic acid molecule consisting essentially of:
 the nucleic acid sequence of SEQ ID NO: 1. 
 
     
     
       2. The aptamer of  claim 1 , wherein when the aptamer consists essentially of the nucleic acid sequence of SEQ ID NO: 1, the aptamer further comprises a forward primer of a nucleic acid sequence of SEQ ID NO: 9, and a reverse primer of a nucleic acid sequence of SEQ ID NO: 10. 
     
     
       3. An aptamer that specifically binds to hemoglobin, wherein the aptamer is a nucleic acid molecule consisting essentially of:
 the nucleic acid sequence of SEQ ID NO: 5. 
 
     
     
       4. The aptamer of  claim 3 , wherein when the aptamer consists essentially of the nucleic acid sequence of SEQ ID NO: 5, the aptamer further comprises a forward primer of a nucleic acid sequence of SEQ ID NO: 13, and a reverse primer of a nucleic acid sequence of SEQ ID NO: 14. 
     
     
       5. A microfluidic chip for detecting the presence of hemoglobin A1c or hemoglobin in blood, comprising the aptamer of SEQ ID. NO: 3 or SEQ ID. NO: 7. 
     
     
       6. A method for detecting the presence and/or amount of hemoglobin A1c and/or hemoglobin, comprising the steps of:
 (a) obtaining a sample of bodily fluid from a subject; 
 (b) contacting the sample with at least one aptamer comprising a hemoglobin A1c-specific nucleic acid sequence or a hemoglobin-specific nucleic acid sequence to allow the aptamer to bind to hemoglobin A1c and/or hemoglobin in the sample, wherein the hemoglobin A1c-specific nucleic acid sequence or the hemoglobin-specific nucleic acid sequence is selected from: the group consisting of a nucleic acid sequence of: SEQ ID NO:1 and SEQ ID NO: 5;and 
 (c) detecting the hemoglobin A1c and/or hemoglobin bound to the aptamer of step (b), whereby presence and/or amount of hemoglobin A1c and/or hemoglobin in the sample is determined,
 wherein, if step (c) is to determine the presence and/or amount of hemoglobin Alc in the sample, an aptamer of SEQ ID NO: 3 comprising the hemoglobin A1c-specific nucleic acid sequence of SEQ ID NO: 1 is selected; if step (c) is to determine the presence and/or amount of hemoglobin in the sample, an aptamer of SEQ ID NO: 7 comprising the hemoglobin-specific nucleic acid sequence of SEQ ID NO: 5 is selected. 
 
 
     
     
       7. The method of  claim 6 , wherein the sample is a blood sample. 
     
     
       8. The method of  claim 6 , wherein the determination of the presence and/or amount of hemoglobin A1c and/or hemoglobin in step (c) further comprises binding the hemoglobin A1c and/or hemoglobin with a light emitting reagent. 
     
     
       9. The method of  claim 8 , wherein the light emitting reagent emits luminescence, fluorescence, visible light, or ultraviolet light.